Angle trisecting device

ABSTRACT

An angle trisecting device for trisecting an angle comprises a substantially plate-like guide member having two sides meeting at substantially right angles to form a corner. A guide rod has a groove formed therein extending along the length thereof. The guide rod extends from the guide member equiangularly between the two sides. Each of a pair of end rods is pivotally affixed at one end to the guide member in the area of the corner thereof and the other end extends beyond the guide member. Each of the pair of end rods is the same angular distance at all times from the guide rod. Each of a pair of struts is pivotally affixed at one end to a corresponding one of the end rods at a point equidistant from the ends of each of the end rods. The struts are pivotally affixed to each other at their other ends and movably mounted in the groove of the guide rod at their other ends. Each of a pair of intermediate rods is pivotally affixed at one end to the guide member at the corner thereof in common with the end rods. Each intermediate rod has a groove formed therein extending along the length thereof. Pivotal coupling means coupling each of the struts at a point equidistant from the ends thereof to a corresponding one of the intermediate rods in a manner whereby each pivotal coupling means is movably mounted in the groove of a corresponding one of the intermediate rods. Each of the end rods and each of the intermediate rods has positioning pins affixed to their other ends and the guide member at the corner has a positioning pin affixed thereto.

' United States Sept. 23, 1975 ANGLE TRISECTING DEVICE [75] Inventor: Joseph J. Romano, East Meadow [73] Assignee: The Raymond Lee Organization,

Inc., New York, NY. a part interest [22] Filed: June 3, 1974 [21] Appl. No.: 475,926

Primary ExaminerRichard E. Aegerter Assistant Examiner-Charles E. Phillips Attorney, Agent, or Firm-Daniel Jay Tick [57] ABSTRACT An angle trisecting device for trisecting an angle comprises a substantially plate-like guide member having two sides meeting at substantially right angles to form a corner. A guide rod has a groove formed therein extending along the length thereof. The guide rod extends from the guide member equiangularly between the two sides. Each of a pair of end rods is pivotally affixed at one end to the guide member in the area of the corner thereof and the other end extends beyond the guide member. Each of the pair of end rods is the same angular distance at all times from the guide rod. Each of a pair of struts is pivotally affixed at one end to a corresponding one of the end rods at a point equidistant from the ends of each of the end rods. The struts are pivotally affixed to each other at their other ends and movably mounted in the groove of the guide rod at their other ends. Each of a pair of intermediate rods is pivotally affixed at one end to the guide member at the corner thereof in common with the end rods. Each intermediate rod has a groove formed therein extending along the length thereof. Pivotal coupling means coupling each of the struts at a point equidistant from the ends thereof to a corresponding one of the intermediate rods in a manner whereby each pivotal coupling means is movably mounted in the groove of a corresponding one of the intermediate rods. Each of the end rods and each of the intermediate rods has positioning pins affixed to their other ends and the guide member at the corner has a positioning pin affixed thereto.

3 Claims, 4 Drawing Figures ANGLE TRISECTING DEVICE DESCRIPTION OF THE INVENTION The present invention relates to an angle trisecting device.

Objects of the invention are to provide an angle trisecting device of simple structure, which is inexpensive in manufacture, is simple and convenient to use, and functions efficiently, effectively and reliably to trisect an angle.

In order that the invention may be readily carried into effect, it will now be described with reference to the accompanying drawing, wherein:

FIG. 1 is a schematic diagram of an embodiment of the angle trisecting device of the invention as it appears in use;

FIG. 2 is a sectional view of the embodiment of FIG. 1 in its folded condition;

FIG. 3 illustrates the trisection of an angle of 90 without the aid of the present invention; and

FIG. 4 illustrates the trisection of an angle of 60 without the aid of the present invention. A

In the FIGS, the same components are identified by the same reference numerals.

The angle trisecting device of the invention, as shown in FIGS. 1 and 2, comprises a substantially platelike guide member having two sides 2 and 3 meeting at substantially right angles to form a corner 4.

A guide rod 5 has a groove 6 formed therein and extending along the length thereof. The guide rod 5 is integrally formed with the guide member 1 and extends beyond the guide member, away from the corner 4, equiangularly between the two sides 2 and 3.

A pair of end rods 7 and 8 are provided. Each of end rods 7 and 8 is pivotally affixed at one end 9 and 10, respectively, to the guide member 1 in the area of the corner 4 thereof. The other end of each of the end rods 7 and 8 extends beyond the guide member. Each of the pair of rods is the same angular distance at all times from the guide rod 5.

A pair of struts 11 and 12 are provided. The strut l 1 is pivotally affixed at one end 13 to the end rod 7 at a point equidistant from the ends of said end rod. The strut 12 is pivotally affixed at one end 14 to the end rod 8 at a point equidistant from the ends of said end rod. The struts l1 and 12 are pivotally affixed to each other at their other ends 15 and 16 and are movably mounted in the groove 6 of the guide rod 5 at said other ends.

A pair of intermediate rods 17 and 18 are provided. Each of the intermediate rods 17 and 18 is affixed at one end 19 and 20, respectively, to the guide member 1 in the area of the corner 4 thereof in common with the end rods 7 and 8, as shown by a single pivot pin 21. Each of the intermediate rods 17 and 18 has a groove 22 and 23, respectively, formed therein and extending along the length thereof.

Pivotal couplings or pivot pins 24 and 25, respec tively, couple the struts 11 and 12, respectively, at a point equidistant from the ends thereof to a corresponding one 17 and 18, respectively, of the intermediate rods in a manner whereby each pivot pin 24 and 25, respectively, is movably mounted in the groove 22 and 23, respectively, of the corresponding one of the intermediate rods 17 and 18, respectively. The pivot pins 24 and 25 are not shown in FIG. 2 in order to maintain the clarity of presentation.

The guide rod 5 extends substantially copanarly with the guide member 1. The end 'rod 7 and the intermediate rod 17 are mounted below the guide member 1. The end rod 8 and the intermediate rod 18 are mounted above the guide member 1.

A plurality of adjustably mounted, lockable pins 26, 27, 28, 29 and 30 extend at substantially right angles from the guide member 1, the end rod 7, the end rod 8, the intermediate rod 17 and the intermediate rod 18, respectively. The pin 26 of the guide member 1 is in the area of the corner 4 of the guide member 1. The pins 27, 28, 29 and 30 of the rods 7, 8, 17 and 18 are at the free ends 31, 32, 33 and 34 thereof. The pins 26, 27, 28, 29 and 30 are for positioning the guide member 1 and the rods on a work sheet v35. 1

As shown in FIG. 3, an angle of is trisected into three angles of 30 by first constructing a square O-A- B-C. The lines O-C and A-B are then bisected t0 establish the points D and E. The line D-E is then drawn. The lines O-A and B-C are bisected to determine the points F and G. The line F-G is drawn. The are C-A is drawn at the point 0, using O-C as the radius. This establishes the points H and K intersecting the lines D-E and F-G.

The arcs C-H, H-K and K-A are equal in length. The

points H and O are joined, as are the points K and O, by lines. The 90 angle C- O-A is thus trisected into three angles of 30 by the lines 0-H and 0-K.

The equilateral triangles O-C-K and O -H-A are then utilized to prove that the 90 is properly trisected.

As shown in FIG. 4, any angle such as, for example, an angle of 60, may be trisected by adding an arc F-G and a line O-K, as well as the lines F-E and E-G. The line F-E is joined to the line O-A at the point F and the line E-G is joined to the line O-D at the point G. The lines F-E and E-G are joined at the point E. The line O-B is joined to the line F-E at the point H and the line O-C is joined to the line E-G at the point J. All the lines A, B, C and D extend to the point 0.

When the lines A, B, C and D are moved toward the line O-K, the points F and G travel along the arc F-G and the point E travels along the line O-K. The line B will not move the same distance as the line O-A, since 7 the. movement of the line B is controlled by the line F-E, whose points E and F travel on two axes while the point H holds the lines F-E and 0-8. This permits the line ()-B to travel one third the distance travelled by the line O-A. The line O-C travels the same distance as the line O-B. The 60 angle A'-O-D' is thus trisected into three angles of 20 by the lines 0-8 and O-C'.

Positive motion is provided, when required, by the guide member 1 and the pin 26. The pin 26 is so positioned that the pivot pin 21 is at the point 0 (FIGS. 3 or 4).

The above procedures with respect to FIGS. 3 and 4 are eliminated by the use of the device of the present invention.

The angle trisecting device of the invention is used by positioning the pivot pin 21 over the vertex of an angle to be -trisected. The end rods 7 and 8 are positioned over the respective sides of the angle by manual movement. As the end rods 7 and 8 move into position over the sides of the angle, they move the intermediate rods 17 and 18, so that said intermediate rods are in angle trisecting positions when said end rods are positioned over the sides of the angle.

While the invention has been described by means of a specific example and in a specific embodiment, I do not wish to be limited thereto, for obvious modifications will occur to those skilled in the art without departing from the spirit and scope of the invention.

I claim:

1. An angle trisecting device for trisecting an angle.

said trisecting device comprising a substantially plate-like guide member having two sides meeting at substantially right angles to form a corner;

a guide rod having a groove formed therein and ex tending along the length thereof, said guide rod extending from the guide member equiangularly between the two sides;

a pair of end rods each pivotally affixed at one end to the guide member in the area of the corner thereof and the other end extending beyond the guide member, each of said pair of rods being the same angular distance at all times from said guide rod;

a pair of struts each pivotally affixed at one end to a corresponding one of the end rods at a point equidistant from the ends of each of the end rods and pivotally affixed to each other at their other ends and movably mounted in the groove of the guide rod at their other ends;

a pair of intermediate rods each pivotally affixed'at one end to the guide member at the corner thereof in common with the end rods and each having a groove formed therein and extending along the length thereof; and

pivotal coupling means coupling each of the struts at a point equidistant from the ends thereof to a corresponding one of the intermediate rods in a manner whereby each pivotal coupling means is movably mounted in the groove of the corresponding one of the intermediate rods, each of the end rods and each of the intermediate rods having positioning means affixed to their other ends and the guide member at said corner having positioning means affixed thereto.

2. An angle trisecting device as claimed in claim 1, wherein the guide rod extends substantially coplanarly with the guide member, one of the end rods and one of the intermediate rods are mounted below the guide member and the other of the end rods and the other of the intermediate rods are mounted above the guide member.

3. An angle trisecting device as claimed in claim 1, wherein the positioning means comprise a plurality of pins extending at substantially right angles from the guide member and each of the end rods and intermediate rods for positioning the member and rods on a work 

1. An angle trisecting device for trisecting an angle, said trisecting device comprising a substantially plate-like guide member having two sides meeting at substantially right angles to form a corner; a guide rod having a groove formed therein and extending along the length thereof, said guide rod extending from the guide member equiangularly between the two sides; a pair of end rods each pivotally affixed at one end to the guide member in the area of the corner thereof and the other end extending beyond the guide member, each of said pair of rods being the same angular distance at all times from said guide rod; a pair of struts each pivotally affixed at one end to a corresponding one of the end rods at a point equidistant from the ends of each of the end rods and pivotally affixed to each other at their other ends and movably mounted in the groove of the guide rod at their other ends; a pair of intermediate rods each pivotally affixed at one end to the guide member at the corner thereof in common with the end rods and each having a groove formed therein and extending along the length thereof; and pivotal coupling means coupling each of the struts at a point equidistant from the ends thereof to a corresponding one of the intermediate rods in a manner whereby each pivotal coupling means is movably mounted in the groove of the corresponding one of the intermediate rods, each of the end rods and each of the intermediate rods having positioning means affixed to their other ends and the guide member at said corner having positioning means affixed thereto.
 2. An angle trisecting device as claimed in claim 1, wherein the guide rod extends substantially coplanarly with the guide member, one of the end rods and one of the intermediate rods are mounted below the guide member and the other of the end rods and the other of the intermediate rods are mounted above the guide member.
 3. An angle trisecting device as claimed in claim 1, wherein the positioning means comprise a plurality of pins extending at substantially right angles from the guide member and each of the end rods and intermediate rods for positioning the member and rods on a work sheet. 